NR ATRD
AU Elfrink,K.; Salwierz,A.; Riesner,D.
TI The cellular prion protein from CHO-cells: Structural conversion and interaction with raft-like lipid membranes
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Structure of PrP and molecular determinants of infectivity STRCT-19
PT Konferenz-Poster
AB
The key role in development of prion diseases is the conversion of the host encoded, mainly alpha-helical, protease-sensitive and non-infectious isoform of the prion protein, PrPc into the insoluble, beta-sheet-rich, protease-resistant and infectious isoform, PrPsc. Within its cellular pathway PrPc undergoes several posttranslational modifications that include the attachment of two N-linked glycans and a glycosyl-phosphatidyl-inositol (GPI) anchor, by which it is linked to the plasma membrane on the exterior cell surface.
To analyze in vitro the influence of the membrane environment on the conversion process we used PrPc from CHO-cells, which carries both, the two N-glycosylations and the GPI-anchor. First we describe the conversion of PrPc into a PrPsc-like structure with respect to an increase in ß-sheet structure and formation of both insolubility and partial protease-resistance. Next to the model experiment in which the anionic detergent SDS mimics a membrane-like environment we extended the system to the in vivo situation by investigating the interaction of PrPc with model plasma membranes by kinetic surface plasmon resonance (SPR) analysis. The results show fast and high affinity binding of PrPc to lipid bilayers. The observation that rekPrP(29-231) shows very low affinity to the bilayer indicates that PrPc-membrane interaction is highly specific and mediated by the GPI-anchor. From these experiments we are able to estimate the concentration of PrPc free in solution but in equilibrium with PrPc bound to the membrane. This situation can be discussed with respect to a two-phase model of prion replication. In addition by specific reconstitution of PrPc into model membranes we established the basis for further analysis on the influence of the membrane environment on PrP-conversion induced by infectious PrPsc-particles.
AD Kerstin Elfrink, Agnieszka Salwierz, Detlev Riesner, Institut für Physikalische Biologie and Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität Düsseldorf, Germany
SP englisch
PO Deutschland